Chemical delivery apparatus for CVD or ALD

ABSTRACT

Embodiments described herein provide ampoule assemblies to contain, store, or dispense chemical precursors. In one embodiment, an ampoule assembly is provided which includes an ampoule containing a first material layer disposed on the outside of the ampoule and a second material layer disposed over the first material layer, wherein the first material layer is thermally more conductive than the second material layer, an inlet line in fluid communication with the ampoule and containing a first manual shut-off valve disposed therein, an outlet line in fluid communication with the ampoule and containing a second manual shut-off valve disposed therein, and a first bypass line connected between the inlet line and the outlet line. In some embodiments, the ampoule assembly may contain disconnect fittings. In other embodiments, the first bypass line has a shut-off valve disposed therein to fluidly couple or decouple the input line and the outlet line.

CROSS-REFERENCE TO RELATED APPLICATIONS

This application is a continuation of U.S. Ser. No. 11/394,448(APPM/010885), filed Mar. 30, 2006, which is herein incorporated byreference in its entirety.

BACKGROUND OF THE INVENTION

1. Field of the Invention

Embodiments of the invention relate to an apparatus and method used forthe delivery of chemical precursors. More particularly, the inventionrelates to an ampoule configured with a valve manifold that includes abypass line and a bypass valve.

2. Description of the Related Art

Chemical vapor deposition (CVD) and atomic layer deposition (ALD) areknown techniques for forming a material on a substrate by the reactionof vapor phase chemicals near the surface of a substrate. In general,CVD and ALD techniques involve the delivery of gaseous reactants to thesubstrate surface where a chemical reaction takes place undertemperature and pressure conditions favorable to the thermodynamics ofthe reaction. The type and composition of the layers that may be formedusing a CVD process or an ALD process are limited by the ability todeliver a chemical reactant or precursor to the substrate surface.Various liquid precursors have been successfully used during CVD and ALDapplications by delivering the liquid precursors within a carrier gas.

A carrier gas is in some cases passed through a heated container, orampoule, which contains a volatile liquid precursor under conditionsconducive to vaporize the precursor. In other cases, a carrier gas ispassed through a heated container containing a solid precursor underconditions conducive to sublimation of the solid precursor. Some gasesthat may be produced through a sublimation process include xenondifluoride, nickel carbonyl, tungsten hexacarbonyl, and pentakisdimethylamido tantalum (PDMAT) among others. In either case, the carriergas combines with the vaporized precursor and both are drawn from thecontainer via dedicated conduits or gas lines to a reaction chamber.Because the chemical precursors for CVD and ALD applications aretypically highly toxic and because the heated container and chemicaldelivery components proximate thereto are generally at an elevatedtemperature, precursor-containing ampoules are typically located insidea protective housing, such as a gas cabinet or gas panel.

A typical gas panel for CVD or ALD applications contains various valves,regulators, and flow controllers in addition to one or moreprecursor-containing ampoules. For safety reasons, gas panels are alsogenerally equipped with exhaust ventilation and are locked and alarmedto prevent possible exposure of personnel to the toxic precursors andheated components located therein. Because the removal and installationof precursor-containing ampoules requires entry into a gas cabinet bymaintenance personnel, it is important to minimize the possibility ofleakage from depleted ampoules when they are being removed and fromfully charged ampoules when they are being installed.

A typical ampoule replacement procedure includes a number of stepsincluding isolation, initial pump-purge, removal/replacement, leakcheck, final pump-purge, and connection.

In the isolation step, the spent precursor ampoule is fluidly isolatedfrom the processing system, typically via manual shut-off valves locatedon the inlet and outlet plumbing of the ampoule. This typically requiresentry into the gas cabinet by maintenance personnel despite proximity togas panel components at elevated temperatures and the presence ofunpurged gas lines containing highly toxic chemicals.

An initial pump-purge is then performed on any gas lines or valves thathave been exposed to toxic agents and which will also be exposed toatmosphere during the ampoule change-out. The pump-purge may includepumping down the appropriate conduits, valves, and other fittings one ormore times with a rough, medium, or high vacuum source, depending on theparticular precursor used. Between pump-downs, the lines and valves maybe purged with a gas, such as an inert gas. In some cases a liquid purgeof conduits and valves may be performed to more efficiently removeunwanted and toxic residues present therein, particularly solid residuesor residues with a very low vapor pressure. The removal of unwantedchemical residues from a conduit or valve via pump/purging is moreeffective when the gas or liquid used for purging can be actively passedthrough the conduit or valve. This is not possible wherever a “dead leg”is present, i.e., a section of pipe or conduit that does not form partof a constant circulation system. Instead, unwanted residues are removedfrom a dead leg by alternately pumping the dead leg down to vacuum andback-filling it with purge fluid, which is known in the art to be lesseffective than the active passage of purge fluid through a conduit orfitting. This is especially true for dead legs that are relatively longand/or contain elbows or other non-linear fittings.

After the pump-purge step has been completed with the requisite numberof pump-purge cycles on the desired conduits, the removal/replacement ofthe ampoule may be performed. In this step, the ampoule is removed fromthe gas cabinet and a fully charged replacement is installed. Theampoule is typically separated from the gas cabinet by means of quickdisconnect type fittings or re-sealable vacuum-tight fittings, such asVCR fittings. In some cases, the fluid delivery system that is exposedto atmosphere as a result of the ampoule replacement is slightlypressurized during the removal/replacement step with an inert gas. Thisslight pressurization minimizes entry into the fluid delivery system ofunwanted contaminants, such as oxygen and/or moisture. The replacementampoule is then connected to the fluid delivery system via theappropriate fittings in the gas cabinet.

Because CVD and ALD precursors are typically highly reactive and in somecases corrosive, it is known in the art that ampoule shut-off valves maynot always be completely leak-tight—particularly after removal of adepleted ampoule from a gas cabinet. This is due to the prolongedexposure of the shut-off valves' sealing surfaces to the precursorchemical flowing therethrough during the lifetime of the ampoule. Anyleakage of the ampoule shut-off valve is a serious issue for tworeasons: the potential for contaminants to enter the ampoule and, moreimportantly, the potential for a dangerous precursor chemical to leakout of the ampoule and expose personnel to toxic chemicals.

After the replacement ampoule is installed, a helium leak check istypically performed on any fluid delivery connection points or otherseals that were broken during ampoule removal/replacement. Thisgenerally involves pumping down the connection points to be tested to arelatively high level of vacuum.

When all connections have passed leak checking, a final pump-purge ofthe fluid delivery system associated with the ampoule replacement isperformed. The final pump-purge is intended to maintain the ultra-highpurity of chemicals delivered to a processing chamber after exposure ofthe fluid delivery system to airborne contaminants, such as moisture andoxygen. As described above for the initial pump-purge, the finalpump-purge step generally includes alternately pumping down and fluidlypurging conduits and other fittings that may have been exposed toatmospheric contaminants. While a final pump-purge step ensures acleaner fluid delivery system for subsequent CVD or ALD processing, itmay also precipitate leakage into or out of the newly charged ampouledue to the additional stresses placed on the ampoule shut-off valveresulting from alternately pressurizing and evacuating a conduit fluidlycoupled thereto.

Finally, after the above steps have been completed, the new ampoule isfluidly connected to the fluid delivery system that terminates in thegas cabinet by opening the manual shut-off valves located on the inletand outlet plumbing of the ampoule. As with the isolation step, thistypically requires entry into the gas cabinet by maintenance personnel.

FIG. 2 is a simplified schematic of a conventional process gas deliverysystem. Fluid delivery system 202 is suitable for producing a processgas containing a chemical precursor and generally includes processchamber 206 and a carrier gas source 205 coupled to gas panel 204, thecomponents of the latter being controlled by a controller 250. Gas panel204 generally controls the rate and pressure at which various processand carrier gases are delivered to process chamber 206. Process chamber206 may be a chamber to conduct vapor deposition processes or thermalprocesses containing a vaporized chemical precursor in liquid, gaseousor plasma state. Process chamber 206 is generally a chemical vapordeposition (CVD) chamber, an atomic layer deposition (ALD) chamber, or aderivative thereof. Examples of process chamber 206 include PRODUCER®CVD chambers and DZX® CVD chambers available from Applied Materials,Inc., located in Santa Clara, Calif. or an ALD chamber, such as thatdescribed in commonly assigned U.S. Pat. No. 6,916,398.

In the configuration illustrated in FIG. 2, controller 250 includescentral processing unit (CPU) 252, memory 254 and support circuits 256.Central processing unit 252 may be one of any form of computer processorthat can be used in an industrial setting for controlling variouschambers and subprocessors. Memory 254 is coupled to CPU 252 and may beone or more of readily available memory such as random access memory(RAM), read only memory (ROM), flash memory, compact disc, floppy disk,hard disk or any other form of local or remote digital storage. Supportcircuits 256 are coupled to CPU 252 for supporting CPU 252 in aconventional manner. These circuits include cache, power supplies, clockcircuits, inpuvoutput circuitry, subsystems, and the like.

Fluid delivery circuit 236 is generally intended to fluidly couplecarrier gas source 205, ampoule 200, and process chamber 206 asnecessary for operation of process chamber 206. Carrier gas source 205may be a local vessel, remote vessel or a centralized facility sourcethat supplies the carrier gas throughout the facility (e.g., in-housegas supply). Carrier gas source 205 typically supplies a carrier gassuch as nitrogen, hydrogen, argon, helium or combinations thereof.Additional purge fluid sources (not shown) may also be fluidly coupledto fluid delivery circuit 236 when the use of specialized purge fluids,such as a purge liquid, is required. Fluid delivery circuit 236typically includes a flow controller 220 disposed between carrier gassource 205 and junction 230 and is adapted to modulate the flow rate ofcarrier gas or other fluids through fluid delivery circuit 236. Flowcontroller 220 may be a proportional valve, a modulating valve, a needlevalve, a regulator, a mass flow controller (MFC) or the like. Junction230 separates fluid delivery circuit 236 into gas generation line 238and bypass line 240. Junction 232 rejoins gas generation line 238 andbypass line 240 before connecting to process chamber 206.

Gas generation line 238 includes ampoule inlet leg 238 a, ampoule outletleg 238 b, valves 208, 210, 212, sensors 226, 228, disconnect fittings262 and 263, and heater 222. Ampoule inlet leg 238 a fluidly couples theinlet of ampoule 200 to carrier gas source 205 and to bypass line 240.Ampoule outlet leg 238 b fluidly couples the outlet of ampoule assembly200 to process chamber 206 and to bypass line 240. Valves 208, 210 and212 are typically remotely controllable shut-off valves that serve todivert the flow of fluids within fluid delivery circuit 236 and/or areused to selectively isolate the various components within fluid deliverycircuit 236 to facilitate removal, replacement and/or service of anisolated component, including sensors 226, 228, heater 222, and ampouleassembly 200. Valves 208, 210, 212, as well as valves 214, 216, 218(described below in conjunction with bypass line 240) are generallypneumatically or electronically controlled and the internal wettedsurfaces thereof are fabricated from materials compatible with theprocess and other fluids handled by fluid delivery circuit 236.Typically, valves 208, 210, 212, 214, 216 and 218 are actuated inresponse to a signal from a controller 250 to coordinate the delivery ofgases through fluid delivery circuit 236. Sensors 226, 228 are generallyadapted to detect the temperature of a process, carrier, and/or purgefluid flowing through gas generation line 238, such as a thermocoupledisposed against a conduit of gas generation line 238.

Bypass line 240 generally includes valves 214, 216 and heater 224 andserves to fluidly couple process chamber 206 and carrier gas source 205without the use of gas generation line 238 or ampoule assembly 200.Valve 218 is generally coupled between junction 232 and process chamber206 and may be used to isolate process chamber 206 from fluid deliverycircuit 236. Heaters 222, 224 are resistive heating elements or otherheat sources adapted to heat a flow of fluid, such as a carrier gas,flowing through gas generation line 238 and bypass line 240,respectively.

Ampoule assembly 200 generally contains an ampoule, or body 270, aninlet line 264, an outlet line 265, disconnect fittings 262 b, 263 b,and manual shut-off valves, manual valves 260 and 261, disposed in inletline 264, 265, respectively. Dead leg conduit segment 271 b is disposedin inlet line 264 between manual valve 260 and disconnect fitting 262and dead leg conduit segment 272 b is disposed in outlet line 265between manual valve 261 and disconnect fitting 263. Ampoule assembly200 may also be referred to as a bubbler, a canister, and other termsknown in the art to describe containers designed and used to store,transport and distribute chemical precursors. Inlet line 264 is coupledto ampoule inlet leg 238 a at disconnect fitting 262 and outlet line 265is coupled to ampoule outlet leg 238 b at disconnect fitting 263.Disconnect fitting 262 and 263 are typically adapted to facilitateremoval and replacement of ampoule assembly 200 in gas panel 204 whileleaving all other components of gas panel 204 in place, such as gasgeneration line 238 and its constituent parts. To this end, disconnectfittings 262 and 263 typically include mating disconnect fittings 262 a,262 b and 263 a, 263 b respectively, wherein disconnect fittings 262 b,263 b are inherent to ampoule assembly 200 and corresponding disconnectfittings 262 a, 263 a are contained in fluid delivery circuit 236.Depending on the application, disconnect fittings 262 a, 262 b and 263a, 263 b may be quick disconnect type fittings, re-sealable vacuum-tightfittings, such as VCR fittings, or other suitable disconnect fittings.

Ampoule assembly 200 may have a variety of sizes and geometries. Ampouleassembly 200 may have a volume capacitance of a chemical precursorwithin a range from about 0.5 L to about 10 L and more typically fromabout 1.2 L to about 4 L. In one example, ampoule assembly 200 has avolume capacitance of a chemical precursor of about 2.5 L. Chemicalprecursors that may be within ampoule assembly 200 include liquid, solidand gaseous precursors, preferably in liquid or fluid-like states atpredetermined temperatures and/or pressures. For example, a chemicalprecursor may exist in the solid state at room temperature, but melts tothe liquid state upon being heated to a predetermined temperature withinthe ampoule. In another example, the majority of a chemical precursormay remain in the solid state in the ampoule, but is heated to anelevated temperature during processing such that a small amount of thesolid precursor sublimates directly into vapor. In another example, achemical precursor may exist in the gaseous state at ambient pressure,but condenses to the liquid state upon being pressurized to apredetermined pressure within the ampoule. Chemical precursors mayinclude alane complexes, such as 1-methylpyrolidrazine:alane (MPA,MeC₄H₃N:AlH₃), pyridine:alane (C₄H₄N:AlH₃), alkylamine alane complexes(e.g., trimethylamine:alane (Me₃N:AlH₃), triethylamine:alane(Et₃N:AlH₃), dimethylethylamine:alane (Me₂EtN:AlH₃)), trimethylaluminum(TMA, Me₃Al), triethylaluminum (TEA, Et₃Al), tributylaluminum (Bu₃Al),dimethylaluminum chloride (Me₂AlCl), diethylaluminum chloride (Et₂AlCl),dibutylaluminum hydride (Bu₂AlH), dibutylaluminum chloride (Bu₂AlCl),water, hydrogen peroxide (H₂O₂), hydrazine (N₂H₄), titaniumtetrachloride (TiCl₄), tetrakis(dimethylamido)titanium (TDMAT,(Me₂N)₄Ti)), tetrakis(diethylamido)titanium (TEMAT, (Et₂N)₄Ti)),bis(ethylcyclopentadienyl)ruthenium ((EtCp)₂Ru),tetrakis(dimethylamido)hafnium (TDMAH, (Me₂N)₄Hf)),tetrakis(diethylamido)hafnium (TDEAH, (Et₂N)₄Hf)),tetrakis(methylethylamido)hafnium (TMEAH, (MeEtN)₄Hf)),tertiaryamylimido tris(dimethylamido)tantalum (TAIMATA,(^(t)AmylN)Ta(NMe₂)₃, wherein ^(t)Amyl is the tertiaryamyl group (C₅H₁₁—or CH₃CH₂C(CH₃)₂—), derivatives thereof, or combinations thereof.

During processing, a carrier gas flows from carrier gas source 205through fluid delivery circuit 236 to ampoule assembly 200. The carriergas may be heated by heater 222, ampoule assembly 200 itself may beheated to a desired temperature, or in some applications, both thecarrier gas and ampoule assembly 200 may be heated. During processing,valves 214 and 216 are closed, directing all carrier gas flow to processchamber 206 via gas generation line 238 and ampoule assembly 200.

During an initial pump-purge procedure performed prior to removing andreplacing ampoule assembly 200, manual valves 260 and 261 are closed.This isolates body 270 from gas generation line 238. During a pump-downsegment of a pump-purge procedure, carrier gas source 205 is alsoisolated from fluid delivery circuit 236 by a shut-off valve (not shown)located between carrier gas source 205 and fluid delivery circuit 236.The vacuum source for process chamber 206 is typically used to pump downfluid delivery circuit 236 and dead leg conduit segments 271 b and 272 bof ampoule assembly 200. Alternatively, a dedicated vacuum source may beused, such as a vacuum pump fluidly coupled to fluid delivery circuit236. In either case, all components of fluid delivery circuit 236 thatare not isolated from the vacuum source are pumped down to a desiredvacuum level, e.g. rough, medium, or high vacuum, by opening therequisite valves in gas panel 204. For example, when the vacuum sourceof process chamber 206 is used for pumping down fluid delivery circuit236, valve 218 is opened to fluidly couple process chamber 206 to fluiddelivery circuit 236, valves 214 and 216 are opened so that bypass line240 fluidly couples ampoule inlet leg 238 a to vacuum, and valves 210and 212 are opened to fluidly couple conduit segments 271, 272 and deadleg conduit segments 271 b and 272 b to vacuum. The desired level ofvacuum targeted during the pump-down segment depends on each particularCVD or ALD application and is a function of factors such as the vaporpressure of precursors and other residues being removed, fluid deliveryline length, etc. It is important to note that it is necessary formaintenance personnel to enter gas panel 204 despite the presence ofunpurged fluid delivery lines in order to close manual valves 260 and261 of ampoule assembly 200.

For a purge segment of a pump-purge procedure, a purge fluid source,such as carrier gas source 205, is fluidly coupled to fluid deliverycircuit 236 and the desired purge fluid is introduced therein. Thedesired purge fluid may be a gas, such as an inert gas or other carriergas, or a liquid, including solvents such as tetrahydrofuran (THF) ortriglyme. Composition of the purge fluid depends on the physical stateand chemical make-up of the chemical residues to be purged, solidparticles and low vapor pressure liquids sometimes requiring one or moreliquid solvent purges. Further, the purge fluid may also be heatedduring the purge segment to aid in the removal of unwanted chemicalresidue, either prior to be introduced into fluid delivery circuit 236or by heaters 222, 224. The vacuum source, such as process chamber 206in one example, may be isolated from fluid delivery circuit 236 duringthe purge segment or it may be fluidly coupled thereto in order tocontinuously remove purge fluid throughout the purge segment. It isimportant to note that active flow of purge fluid occurs principallyalong bypass line 240 during a purge procedure. The only active flow ofpurge fluid into ampoule inlet leg 238 a and ampoule outlet leg 238 boccurs when these two sections of fluid delivery circuit are back-filledwith purge fluid at the beginning of a purge segment. Hence, ampouleinlet leg 238 a and ampoule outlet leg 238 b act as extensive dead legsof significant length and potentially include numerous flow-restrictingelbows. Further, the regions of fluid delivery circuit 236 that will beexposed to atmosphere during ampoule replacement, i.e. conduit segments271, 272, and dead leg conduit segments 271 b and 272 b, are most likelyto be contaminated and are the most important to purge thoroughly inpreparation thereof. However, conduit segments 271, 272, and dead legconduit segments 271 b and 272 b are located at the distal ends of theabove-described dead legs and are, therefore, the most difficult regionsof fluid delivery circuit 236 to purge effectively.

During removal, valves 210 and 212 are closed to fluidly isolate conduitsegments 271, 272 from fluid delivery circuit 236, and disconnectfittings 262 and 263 are separated to allow removal of ampoule assembly200, wherein mating disconnect fittings 262 b, 263 b inherent to ampouleassembly 200 and are removed therewith. As noted above, it is known inthe art that ampoule shut-off valves, i.e. manual valves 260 and 261,may not always be completely leak-tight after prolonged exposure to theprecursor chemicals contained in ampoule assembly 200. Because a singlepoint of isolation is used for ampoule assembly 200 at inlet line 264and outlet line 265, i.e. manual valves 260 and 261, respectively, thereis the potential of leakage into or out of ampoule assembly 200 duringthe removal of a depleted ampoule from gas panel 204. A freshly-chargedampoule is reconnected to fluid delivery circuit 236 at disconnectfittings 262 and 263.

After installation of a new ampoule assembly 200, any fluid deliveryconnection points or other seals that were broken during ampouleremoval/replacement are leak-checked, in this example disconnectfittings 262 and 263. Leak checking ensures that contaminants are notdrawn into fluid delivery circuit 236 and that toxic chemical precursorsdo not leak out of ampoule assembly 200 during processing. If either ofdisconnect fittings 262 and 263 are not vacuum-tight, only a singlepoint of isolation is present between the chemical contents of ampouleassembly 200 and any contaminants that may have leaked into dead legconduit segments 271 b and 272 b.

Therefore, there is a need for an apparatus and process to purge gaslines as completely as possible, to perform pump-purge procedures withminimal entry into a gas cabinet, and to decrease the possibility ofleakage into or out of precursor-containing ampoules before, during, andafter removal and installation of such ampoules.

SUMMARY OF THE INVENTION

Embodiments of the present invention provide an apparatus used for thedelivery of chemical precursors and a method for purging said apparatus.In one embodiment, an ampoule assembly comprises an inlet line, anoutlet line, and a bypass line connected between the inlet line and theoutlet line, the bypass line having a shut-off valve disposed therein tofluidly couple or decouple the input line and the outlet line. Theampoule assembly may further comprise manual shut-off valves disposed inthe input and output lines and remotely controllable shut-off valvesdisposed in the inlet and the outlet lines respectively between theampoule and the manual shut-off valves. In one aspect, the ampouleassembly comprises one or more thermally conductive coatings thatimprove the uniformity of temperature inside the ampoule body.

Embodiments of the present invention also provide a method for purgingfluid lines of an ampoule assembly including an input line, an outputline, and a bypass line connecting the input line and the output line.The method according to an embodiment includes remotely opening a valvedisposed in the bypass line, remotely closing valves disposed in theinlet and outlet lines, and pump-purging the bypass line and other linesand valves fluidly coupled thereto.

BRIEF DESCRIPTION OF THE DRAWINGS

So that the manner in which the above recited features of the presentinvention can be understood in detail, a more particular description ofthe invention, briefly summarized above, may be had by reference toembodiments, some of which are illustrated in the appended drawings. Itis to be noted, however, that the appended drawings illustrate onlytypical embodiments of this invention and are therefore not to beconsidered limiting of its scope, for the invention may admit to otherequally effective embodiments.

FIG. 1 (Prior Art) is a simplified schematic of a process gas deliverysystem that employs a conventional ampoule assembly.

FIGS. 2A-2C are schematic diagrams of a fluid delivery system to whichan ampoule assembly has been fluidly coupled.

FIGS. 3A-3H are schematic diagrams of a chemical-containing containeraccording to different embodiments of the invention.

FIG. 4A is a perspective view of the chemical-containing container ofFIG. 3A.

FIG. 4B is a perspective view of the chemical-containing container ofFIG. 3B.

FIG. 5 illustrates a process sequence for pump-purging an ampouleassembly.

FIGS. 6A-6B schematically illustrate one embodiment of an ampouleassembly with easily serviceable shut-off valves.

For clarity, identical reference numerals have been used, whereapplicable, to designate identical elements that are common betweenfigures.

DETAILED DESCRIPTION

Aspects of the invention contemplate a chemical-containing ampoule orcontainer having an inlet conduit and an outlet conduit and beingconfigured to include a bypass conduit and a remotely controllable valvefluidly connecting the inlet and outlet conduits. Aspects alsocontemplate a pair of shut-off valves configured in series on both theinlet and outlet conduits of the ampoule, wherein each pair of valvesincludes a positive sealing manual valve, such as a ¼-turn ball valve,and a remotely controllable valve, such as a pneumatic valve. Aspectsfurther contemplate charging or back-filling some or all components of achemical-containing ampoule with an inert gas, such as He. In oneexample, the body and inlet and outlet lines of a precursor-containingampoule assembly are charged with an inert gas above atmosphericpressure. In another example, segments of the inlet and outlet lines ofa precursor-containing ampoule assembly are charged with an inert gasabove atmospheric pressure. Another aspect of the invention contemplatesan ampoule body that provides more uniform heating of its contents viaone or more layers of a thermally conductive coating.

For reasons of chemical compatibility and mechanical strength, body 270is typically made of 316 stainless steel (316 SST). Chemical inertnessis an important requirement for body 270 since the majority of chemicalprecursors, such as those listed above, are highly reactive materials.Substantial mechanical strength is a requirement for body 270 since body270 of ampoule assembly 200 may operate at vacuum during processing yetmay be pressurized above atmospheric pressure for transport and storage.Hence, body 270 must act as a reliable containment vessel for a toxicchemical precursor while utilized as a vacuum chamber or as a pressurevessel.

Because 316 SST is a poor medium for thermal conductivity, undesirablethermal gradients may develop inside body 200 during processing. Forexample, when a liquid chemical precursor is contained inside body 200,more and more volume of body 200 is vapor-filled as the liquid precursoris depleted, poor thermal conductivity of body 200 may result in unevenheating, i.e., “hot spots,” in the liquid precursor later in the life ofthe ampoule. In another example, such as when body 200 contains a solidchemical precursor, poor thermal conductivity of body 200 may create hotspots throughout the life of the ampoule. In either case, a CVD or ALDprocess may be detrimentally affected by such temperaturenon-uniformities.

In order to improve the temperature uniformity of a chemical precursorcontained in ampoule assembly 200, aspects of the invention contemplatea configuration of body 270 wherein body 270 is enhanced with athermally conductive layer 270 a of thermally conductive material toimprove heat conduction throughout body 270, as depicted in FIG. 3A.Thermally conductive layer 270 a may be a simple coating or may be aninterlayer sandwiched between an inner and an outer layer of a strongerbut less thermally conductive material, such as 316 SST. FIG. 3Gillustrates a partial sectional schematic view of body 270, whereinthermally conductive layer 270 a is sandwiched between two layers 270 band 270 c of one or more mechanically stronger materials. FIG. 3Hillustrates a partial sectional schematic view of body 270, whereinmultiple thermally conductive layers 270 a are sandwiched betweenmultiple layers 270 d-270 f of one or more mechanically strongermaterials to form a layered structure. Thermally conductive layer 270 ais illustrated as a coating of body 270 of ampoule assembly 300A in FIG.3A, however thermally conductive layer 270 a may easily be incorporatedinto the embodiments illustrated in FIGS. 3B-3F as well. Thermallyconductive layer 270 a may be applied to body 270 by electroplating orany other coating method. Examples of possible materials for 270 ainclude aluminum, copper, silver, brass, or any other thermallyconductive material that is substantially more heat conducting than thematerial comprising the bulk of body 270. The thickness of layer 270 amay range from a few microns to several millimeters. For example, thethickness may be between about 1 micrometer and about 5 millimeters.

FIG. 3A is a schematic diagram of one aspect of the invention, wherein achemical-containing ampoule or container, ampoule assembly 300A, isconfigured with an inherent bypass conduit 302 with a remotelycontrollable valve disposed 301 therein. FIG. 4A is a perspective viewof ampoule assembly 300A. Valve 301 may be actuated pneumatically, by anelectric motor, or by any other remotely-controllable means. Ampouleassembly 300A, bypass conduit 302, valve 301 and manual valves 260 and261 are adapted to be a unitary assembly during removal and replacementof ampoule assembly 300A. Ampoule assembly 300A may be fluidly coupledto a gas panel, such as gas panel 204 illustrated in FIG. 2A, viadisconnect fittings 262 b and 263 b. FIG. 2A is a schematic diagram of afluid delivery system 235A to which ampoule assembly 300A has beenfluidly coupled. Except for the substitution of ampoule assembly 300Afor ampoule assembly 200, fluid delivery system 235A is substantiallyidentical to fluid delivery system 202 in function and organization asdescribed above in conjunction with FIG. 2.

This aspect allows the effective pump-purge of gas generation line 238and its constituent parts via the active passage of purge fluidtherethrough. Referring to FIG. 2A, during a pump-purge procedure,valves 214, 216 may be closed, forcing all purge fluids through ampouleinlet leg 238 a, bypass conduit 302, and ampoule outlet leg 238 b.During pump-purge procedures, the only remaining dead legs in fluiddelivery circuit 236 are dead leg conduit segments 271 b and 272 b,which may be as short as 1-3 cm and, further, are without any elbows orother impediments to fluid flow. Hence dead leg conduit segments 271 band 272 b, which in this aspect are short, straight dead legs, can bemore effectively purged before and after replacement of ampoule assembly300A.

FIG. 3B is a schematic diagram of another aspect of the invention,wherein a chemical-containing ampoule or container, ampoule assembly300B, is configured with two additional remotely controllable shut-offvalves, valves 267 and 268 as well as with bypass conduit 302 withremotely controllable valve 301 disposed therein. FIG. 4B is aperspective view of ampoule assembly 300B. Valves 267 and 268 may beactuated by a number of remotely-controllable means as detailed abovefor valve 301 in conjunction with FIG. 3A. Ampoule assembly 300B, bypassconduit 302, manual valves 260 and 261, and valves 301, 267 and 268 areadapted to be a unitary assembly during removal and replacement ofampoule assembly 300B. Ampoule assembly 300B may be fluidly coupled togas panel 204 as illustrated in FIG. 2B. FIG. 2B is a schematic diagramof a fluid delivery system 235B to which ampoule assembly 300B has beenfluidly coupled. Except for the substitution of ampoule assembly 300 forampoule assembly 200, fluid delivery system 235B is substantiallyidentical to fluid delivery system 202 in function and organization asdescribed above in conjunction with FIG. 2.

This aspect allows the effective pump-purge of gas generation line 238and its constituent parts via the active passage of purge fluidtherethrough as described above in the previous aspect. In addition,maintenance personnel may perform a pump-purge procedure prior toampoule replacement without entry into gas panel 204. Valve 301 andvalves 267 and 268 may be closed remotely via controller 250, fluidlycoupling ampoule inlet leg 238 a and ampoule outlet leg 238 b to avacuum source, such as process chamber 206, and a purge fluid source,such as carrier gas source 205. This is an important safety advantagesince entry into gas panel 204 and manipulation of manual valves thereinis not required until fluid delivery circuit 236 has been safelypump-purged. Ordinarily, maintenance personnel must enter gas panel 204to close manual valves 260 and 261 prior to initiating pump-purgeprocedures. Further, ampoule assembly 300B has two points of isolationfrom ambient contamination for inlet line 264 and outlet line 265,namely manual valve 260, valve 267 and manual valve 261, valve 268,respectively. This redundancy minimizes the risk of leakage into or outof ampoule assembly 300B in the event that manual valves 260 and 261 arenot leak-tight. As noted above, there is ordinarily only a single pointof isolation for the contents of an ampoule during ampoule removal, leakchecking, and pump-purging.

FIG. 5 illustrates a process sequence 500 for pump-purging ampouleassembly 300B. In step 501, valves 267 and 268 are closed remotely viacontroller 250, isolating body 270 from ampoule inlet leg 238 a andampoule outlet leg 238 b. In the step 502, bypass valve 301 is openedremotely via controller 250, fluidly coupling ampoule inlet leg 238 a,ampoule outlet leg 238 b and the majority of inlet line 264 and outletline 265. The vacuum source may be the vacuum source associated withprocess chamber 206. In step 503, fluid delivery circuit 236, bypassconduit 302, inlet line 264, and outlet line 265 are pumped down to thedesired level of vacuum. In step 504, a purge fluid, such as a carriergas or in some cases a liquid solvent, is then flowed through theevacuated lines. Heater 222 may heat the purge fluid, if desired. Whenthe purge fluid source is configured relative to fluid delivery circuit236 as illustrated in FIG. 2B, the purge fluid enters ampoule assembly300B via ampoule inlet leg 238 a, flows through bypass conduit 302, andleaves ampoule assembly 300B via ampoule outlet leg 238 b. In addition,the purge fluid back-fills the portions of inlet line 264 and outletline 265 fluidly coupled to bypass conduit 302. The duration and flowrate of purge fluid flow through ampoule assembly 300B is dependent onthe purge fluid used, conduit size, chemical composition of unwantedresidues, and quantity thereof present in the lines. In step 505,completion of pump-purge procedure is checked. If the purging of thedesired lines is complete, the process continues to step 506, whereinampoule assembly 300B is removed from gas panel 204. If furtherpump-purge steps are desired, the process returns to step 503. Thenumber of pump-purge iterations desired is variable, depending on suchfactors as the purge fluid used, conduit size, chemical composition ofunwanted residues, and quantity thereof that may be present in thelines.

FIG. 3C is a schematic diagram of another aspect of the invention. Inthis aspect, ampoule assembly 300C is configured with an inherent valveassembly similar to that of ampoule assembly 300B, as illustrated inFIG. 3B. An inherent bypass conduit 302C that has a remotelycontrollable valve 301C disposed therein fluidly couples dead legconduit segments 271 b and 272 b as in the previous two aspects, but inthis aspect, the connection points of bypass conduit 302C to dead legconduit segments 271 b and 272 b are located at junctions 315, 316,respectively. Junction 315 is disposed between manual valve 260 andvalve 267 and junction 316 is disposed between manual valve 261 andvalve 268. Ampoule assembly 300C may be fluidly coupled to gas panel 204as illustrated in FIG. 2C. FIG. 2C is a schematic diagram of a fluiddelivery system 235C to which ampoule assembly 300C has been fluidlycoupled. Except for the substitution of ampoule assembly 300C forampoule assembly 200, fluid delivery system 235C is substantiallyidentical to fluid delivery system 202 in function and organization asdescribed above in conjunction with FIG. 2.

This aspect allows the effective pump-purge of gas generation line 238and its constituent parts as described above for the previous aspects ofthe invention. In addition, this aspect provides a means of activelypassing a purge fluid through manual valves 260 and 261 during apump-purge procedure. Referring to FIGS. 2C and 3C, valve 301C andvalves 267 and 268 may be closed remotely via controller 250, allowingvalves 267 and 268 to be more thoroughly purged prior to removal ofampoule assembly 300C. In addition, the size of dead legs present duringthe pump-purge procedure are reduced to the dead leg conduit segments271 b and 272 b, i.e. the conduit segment located between junction 315and valve 267 and the conduit segment located between junction 316 andvalve 268. Hence, the dead leg conduit segments 271 b and 272 b for thisaspect are substantially reduced in length when compared to dead legconduit segments 271 b and 272 b for the previous aspect shown in FIG.3B.

FIG. 3D is a schematic diagram of another aspect of the invention. Inthis aspect, ampoule assembly 300D is configured with an inherent valveassembly similar to that of ampoule assembly 300C, as illustrated inFIG. 3C. An inherent bypass conduit 302D that has a remotelycontrollable valve 301D disposed therein fluidly couples dead legconduit segments 271 b and 272 b as in the previous two aspects, but inthis aspect there is a second bypass conduit 304D configured with aremotely controllable valve 303D disposed therein. Ampoule assembly 300Dmay be fluidly coupled to gas panel 204 as illustrated for ampouleassemblies 300A-300C in FIGS. 2A-2C.

FIGS. 3E-3F illustrate two other aspects of embodiments of theinvention. Ampoule assemblies 300E and 300F are each configured with aninherent valve assembly similar to that of ampoule assembly 300C, asillustrated above in FIG. 3C. In the aspect illustrated in FIG. 3E,bypass conduit 302E and remotely controllable valve 301E disposedtherein fluidly couple inlet line 264 with outlet line 265. Bypassconduit 302E is connected to inlet line 264 between manual valve 260 andvalve 267 and is connected to outlet line 265 between manual valve 261and disconnect fitting 263 b. In the aspect illustrated in FIG. 3F,bypass conduit 302F and remotely controllable valve 301 F disposedtherein fluidly couple inlet line 264 with outlet line 265. Bypassconduit 302F is connected to inlet line 264 between manual valve 260 anddisconnect fitting 262 b and is connected to outlet line 265 betweenmanual valve 261 and valve 268.

As noted above, in some aspects of the invention, some or all componentsof a chemical-containing ampoule are charged with an inert gas, such asHe. The advantages of this are twofold. First, charging the ampoule bodywith a pressurized atmosphere of an inert gas chemically protects theprecursor contained therein, even if some leakage occurs through any ofthe seals or valves in the ampoule assembly. This is particularly truefor a solid precursor-containing ampoule assembly. Second, during aleak-checking procedure, such as that described above in conjunctionwith FIG. 2, a helium charge in the inlet line allows for leak-checkingafter new ampoule installation of not only of leakage into disconnectfittings 262 and 263 from outside fluid delivery system 202 (see FIG.2), but also of leakage through the outermost shut-off valve located ininlet line 264 and outlet line 265, such as manual valves 260 and 261.It is important to note that the typical leak rate through shut-offvalves, such as manual valves 260 and 261, is much higher than thetypical leak rate externally, i.e., through the external seals of saidvalves, hence, checking for leakage through manual valves 260 and 261 isan important procedure. In instances wherein it is undesirable for theampoule body to be charged with an inert gas, which may be the case forcertain liquid precursors, only a segment of the inlet and outlet linesmay be charged with the inert gas. For example, referring to FIG. 2B,the segment of inlet line 264 disposed between manual valve 260 andvalve 267, and the segment of outlet line 265 disposed between manualvalve 261 and valve 268, may be the only regions of ampoule assembly300A charged with an inert gas.

A more detailed description of a precursor-containing ampoule that maybe contained in some configurations of the invention may be found incommonly assigned U.S. Ser. No. 11/246,890, filed Oct. 7, 2005, andpublished as US 2007-0079759, which is hereby incorporated by referencein its entirety to the extent not inconsistent with the claimedinvention.

As noted above, the sealing surfaces of shut-off valves that are exposedto highly reactive chemical precursors for extended periods, such asmanual valves 260 and 261 (shown in FIGS. 2A-2C), may be damaged andfail to seal as desired. This is particularly true when an ampouleassembly contains a solid precursor. Solid precursors dissolved by aheated carrier gas may subsequently precipitate out of the carrier gasif not maintained at the necessary temperature and condense ontoshut-off valve sealing surfaces, hindering a vacuum-tight seal andrequiring valve replacement. Because valve replacement for ampouleassemblies occurs relatively frequently, ease of serviceability is alsoan important consideration.

FIGS. 6A and 6B schematically illustrate one embodiment of ampouleassembly 600 with easily serviceable shut-off valves. FIG. 6A is aschematic side view and FIG. 6B is a schematic top view. Ampouleassembly 600 includes valve assembly 610, ampoule body 270, inletconnection 620, and outlet connection 621. Inlet connection 620 ispreferably a ¼ inch VCR connection and outlet connection 621 ispreferably a ½ inch VCR connection for ease of repeated installation andremoval of ampoule assembly 600 from a processing system. Valve assembly610 includes shut-off valves 611 and 612, which are also configured tobe easily removed. Shut-off valves 611 and 612 are preferably mounted tovalve assembly 610 via VCR fittings (not shown for clarity) andpositioned to have a convenient clearance from other components of valveassembly 610 and ampoule assembly 600. In one example, shut-off valves611 and 612 are positioned 3.25 inches apart to allow adequate accessfor removal from and installation in valve assembly 610.

While the foregoing is directed to embodiments of the invention, otherand further embodiments of the invention may be devised withoutdeparting from the basic scope thereof, and the scope thereof isdetermined by the claims that follow.

1. An ampoule assembly, comprising: an ampoule comprising a firstmaterial layer disposed on the outside of the ampoule and a secondmaterial layer disposed over the first material layer, wherein the firstmaterial layer is thermally more conductive than the second materiallayer; an inlet line in fluid communication with the ampoule andcomprising a first manual shut-off valve disposed therein; an outletline in fluid communication with the ampoule and comprising a secondmanual shut-off valve disposed therein; and a first bypass lineconnected between the inlet line and the outlet line.
 2. The ampouleassembly of claim 1, further comprising at least one disconnect fitting.3. The ampoule assembly of claim 2, further comprising two or moredisconnect fittings.
 4. The ampoule assembly of claim 2, wherein thefirst bypass line has a shut-off valve disposed therein to fluidlycouple or decouple the input line and the outlet line.
 5. The ampouleassembly of claim 1, wherein the second material layer is a coating onthe outer surface of the first material layer.
 6. The ampoule assemblyof claim 5, wherein the second material layer is mechanically strongerthan the first material layer.
 7. The ampoule assembly of claim 1,wherein the first material layer comprises a metal selected from thegroup consisting of aluminum, copper, silver, brass, and combinationsthereof.
 8. The ampoule assembly of claim 7, wherein the first materiallayer has a thickness within a range from about 1 micrometer to about 5millimeters.
 9. An ampoule assembly, comprising: an ampoule; an inletline in fluid communication with the ampoule; an outlet line in fluidcommunication with the ampoule; a bypass line connected between theinlet line and the outlet line, the bypass line having a first valvedisposed therein to fluidly couple or decouple the input line and theoutlet line; a first manual shut-off valve disposed in the inlet linebetween the ampoule and The connection point of the bypass line and theinlet line; a second manual shut-off valve disposed in the outlet linebetween the ampoule And the connection point of the bypass line and theoutlet line; a second valve disposed in the inlet line between thebypass line and the ampoule; and at least one disconnect fitting on theinlet line or the outlet line.
 10. The ampoule assembly of claim 9,wherein the inlet line and the outlet line each contain a disconnectfitting.
 11. The ampoule assembly of claim 10, further comprising athird valve disposed in the outlet line between the bypass line and theampoule.
 12. The ampoule assembly of claim 9, wherein the ampoulecomprises: at least one layer of a first material; and at least onelayer of a second material, wherein the first material is thermally moreconductive than the second material.
 13. The ampoule assembly of claim11, wherein the first, second, and third valves are remotelycontrollable shut-off valves.
 14. The ampoule assembly of claim 13,wherein the first manual shut-off valve is disposed in the inlet linebetween the second remotely controllable shut-off valve and the bypassline and the second manual shut-off valve is disposed in the outlet linebetween the third remotely controllable shut-off valve and the bypassline.
 15. The ampoule assembly of claim 12, wherein the bypass line isconnected to the input line at a point that is between the first manualshut-off valve and the ampoule, and wherein the bypass line is connectedto the output line at a point that is between the second manual shut-offvalve and the ampoule.
 16. The ampoule assembly of claim 15, furthercomprising: a second bypass line connected between the inlet line andthe outlet line; and a fourth remotely controllable shut-off valvedisposed in the second bypass line to fluidly couple or decouple theinput line and the outlet line, wherein: the first manual shut-off valveis disposed between the connection point of the first bypass line andthe inlet line and the connection point of the second bypass line andthe inlet line; and the second manual shut-off valve is disposed betweenthe connection point of the first bypass line and the outlet line andthe connection point of the second bypass line and the outlet line. 17.The ampoule assembly of claim 12, wherein the first material comprises ametal selected from the group consisting of aluminum, copper, silver,brass, and combinations thereof.
 18. The ampoule assembly of claim 9,wherein the ampoule contains a chemical precursor used for vapordeposition processes.
 19. The ampoule assembly of claim 18, wherein thechemical precursor comprises a tantalum precursor.
 20. The ampouleassembly of claim 19, wherein the tantalum precursor comprisespentakis(dimethylamido)tantalum or tertiaryamylimido tris(dimethylamido)tantalum.